Sanchez failed to inform drugs testers of his whereabouts on Monday, as his transfer from Arsenal to Manchester United was pushed through.

UK Anti-Doping officers were unable to locate him despite a trip to Arsenal’s training ground, and on Friday Arsene Wenger admitted Arsenal shouldbear responsibility for not informing the authorities the Chile forward would not be at the club’s Colney base.

Sanchez laid on two goals on his United debut as Mourinho’s side overwhelmed Yeovil 4-0 at Huish Park on Friday night to move into the FA Cup fifth round, before Mourinho insisted the drugs test issue was an honest mix-up.

“I think Arsenal were very honest in the way they approached the situation,” said Mourinho, of Sanchez’s missed drugs test.

“We all know we must tell the whereabouts, our players where they are 24 hours a day.

“Nobody knew where he was going to be, it was just a period of his transfer.